Screw lifting-jack.



SCREW LIFTING JACK.

' Patented Jan. 7, 1913.

APPLICATION FILED MAY 1 1911 Q/Vi hwooeo RAP" CO-,WASHINGTON. b. c

COLUMBIA PLANOG (UNITED: STATES QFFIOE- EUGENE COOK, OEKALAMAZOO, MICHIGAN, ASSIGNOR To vmerivm R. cook," or" To all whom it may concern:

KALAMAzoo, MICHIGAN.

SCREW unwind-JACK.

-' Be-it known that LEUGE-NE Coon, a citi- .zenof the United States, residing at Kalamazoo, county of Kalamazoo, State of Michigan, have invented certain new and useful Improvements in Screw Lifting-- Jacks, of which the following is a specification; 1

This invention relates to improvements in screw lifting jacks. V

A My improvements are particularly de signed by me for use on small jacks, such as the so-called automobile jacks: that is, jacks especially designed for lifting automobiles, and I have shown the same. embodiedin such a small size jack. My in- I 1 vention, however, is applicable to jacks of various sizes for generalnse.

The main objectsofwthis invention are:j

First, to provide an improved screw lifting jack by means of which the 'load'may, be very rapidly raised or lowered. Second, to provide an improved screw lifting jack which is very quickly adjusted to the load.

Third, to provide an improved screw lifting jack which is simple in structure and very simple and convenient to use.

Further objects, and objects relating to structural details, will definitely appear from the detailed description to follow.

I accomplish theobjects of my invention by the devices and .means described in the following specification. I j I The invention is clearly defined and pointed out in the claims.

A Structure which is a preferred embodipart of this specification, in which:

Figure I is a side view of my improved lifting jack, a portion of the standard being broken away. Fig. II is a vertical section taken on a line corresponding to the broken line 2-2 of Fig. I. Fig. III is-a horizontal section taken on a line corresponding to line 33 of Fig. I.' Fig. IV is a horizontal section taken on a line corresponding to" line 44 of Fig I, the pin 6 being shown in full lines.

In the drawing, similar reference characters refer to similar parts throughout the several views, and the sectional views are taken looking in the direction of the little I manufacture and is not likely to get outof V arrows at the ends of the section linesfl :as stated.

Sean "N0. 624,36?

Referring to the drawing, the standard 1 is provided with a base 2, the standard being cylindrical, as illustrated, and having opposed longitudinalribs 8 for the purpose of strengthening the standard. The internal vertical grooves 4 are located opposite these ribshThe screw.5 is fvertically movable in the standard, and is prevented Patented Jan. 7,1913.

from turningtherein by meansof the pin 6 arranged transversely through, the lower end of the screw to engagefthe grooves 4. The standard is shouldered at 7 to provide a bearing for the rack gear 8, which gear is arranged in mesh with the driving gear 9. The gear 9 is supported by a bearing pin 10 and is provided with an actuatinglever 11, the movement ofthe gear being an oscillating movement. The circular rack '12, is j formed integrally with the gear 8.. Bearing on the upper end of the standard is a mm 13, which is provided with a laterallyprojecting arm 14 onwhich the pawl 15 is pivoted. The arm is provided with a pair of ears 16. for the pawl pin 17. Thepawl is reversible: that is, it is adapted "to'be swung toeither side of the arm and is provided with double pallets '18. I The nut 13 is unattached to the standard, so that in adjusting ,the'jack to the work, the screw may belifted and the nut rapidly turned either up or down by hand, as may be necessary, to extend or retract the'screw to'adjust it to the work. M

In raisingon lowering the load, the pawl '15 is adjusted asxi'nay be required to either raise or lower the screw; and the rack oscil- 'lated through the lever'll and its gear 9.

The jack is reversed merely by the reversing of the pawl.

Screw jacks, 'as; ordinarily constructed, have not been adapted for use where rapid work was required, they being particularly desirable where great power was desired. 'By my improvements, I provide a screw jack withwhichit is possible to rapidly raise or lower the load, "and one which may be'reversed merely by reversing the pawl,

As previously remarked, my improvements are especially designed by me for embodiment in light jacks, such as automobilejacks.

The structure is simple and economical to ters Patent is 1. In a jack, the combination with the standard, of a screw arranged in said standard, sald standard having vertical opposed grooves and said screw a transverse pm engaging said grooves; a beveled gear having a circular rack on its upper side, said standard being shouldered at its upper end to provide a bearing for said gear; a nut arranged to bear on the upper end of said standard, said nut being provided with a laterally-projecting pawl arm; a pawl pivoted on said arm to be reversed thereon; a driving gear mounted on said standard in mesh with said rack; and a lever on said driving gear.

2. In a jack, the combination with the standard, of a screw arranged in said standard; a beveled gear having a circular rack on its upper side, said standard being shouldered at its upper end to provide a bearing for said gear; a nut arranged to bear on the upper end of said standard independently of said rack, said nut being provided with a laterally-projecting pawl arm; a

pawl pivoted on said arm to be reversed i thereon; a driving gear mounted on said standard in mesh with said rack; and a lever on said driving gear.

8. In a jack, the combination with the standard, of a screw; a circular rack mounted on said standard; means for oscillating said rack; a nut having bearing engagement with the top of said standard independently of said rack, said nut being unattached to said standard to permit the raising of the standard and nut and the adjustment of the nut on the screw independently of the rack; and a reversible pawl on said nut coacting with said rack, for the purpose specified.

4:. In a jack, the combination with the standard, of a non-rotatable screw, a gear having a rack on its upper face mounted on said standard; means for driving said gear; a nut on said screw bearing on said standard independently of said gear; and a reversible pawl on said nut, coacting with said rack.

In witness whereof, I have hereunto set my hand and seal in the presence of two witnesses.

EUGENE COOK. [L. s.] Witnesses a M. P. WOODRUFF, L. G. GREENFIELD.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. O. 

